This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
AP access point
DNS domain name system
DNS-SD DNS service discovery
DTIM delivery traffic identification message
GAS generic advertisement service
GASTIM generic advertisement service traffic indication message
IBSS independent basic service set
IEEE Institute of Electrical and Electronics Engineers
IE information element
L2 layer 2
L3 layer 3
L2SD layer 2 service discovery
MAC medium access control layer
MLME MAC layer management entity
MP mesh point
PHY physical layer
SSDP simple service discovery protocol
SAP service access point
STA station
UPnP universal plug and lay
WFA WiFi Alliance
WLAN wireless local area network
A device in communication network uses service discovery to get information of the offered services in another device or network. Service discovery in WLAN networks may be done at layer 3 (L3) and above. It may be based on the GAS procedure and relying on the protocols which run on top of the IP layer. The most widely used service discovery protocols are the ones specified in UPnP and Zeroconf (Zero Configuration Networking): namely SSDP and DNS-SD. Use of these protocols requires the client device to connect to the WLAN network and configure its IP layer, which is both time and power consuming. This has resulted in proposals to allow service discovery before network selection, which requires service information to be available at the WLAN MAC level, i.e. at layer 2 [thus the terminology Layer 2 service discovery (L2SD)]. STA may initiate service discovery by sending a GAS initial request frame. The STA may send the GAS initial request frame because the service information is not included in the beacon or probe response(s). Thus, the STA needs to complete a message exchange sequence to obtain the service information. In beacon and probe responses, an AP can inform a STA as to whether or not the AP supports GAS.
These teachings specify particulars of exemplary implementation mechanisms for L2SD.